The use of membranes to effect separation of gas/gas mixtures and liquid/liquid mixtures has achieved general industrial applicability for various methods, such as ultrafiltration, reverse osmosis, and gas separation. Recently, attention has been particularly given to gas separation which is effective in the separation of such mixtures as oxygen/nitrogen, carbon dioxide/methane, and hydrogen/methane to name a few.
The hollow fiber membrane configuration is currently the most common membrane configuration in gas separations with processes generally carried out at elevated pressures from about 100 up to about 2,000 psi and temperatures ranging from room temperature up to about 100.degree. C.
Hollow fiber membrane fluid separation apparatus for the separation of a first component from at least one other component in a mixture of fluids that can be comprised of liquids or gases has numerous embodiments in the art. The most frequent configuration involves the use of a single bundle of hollow fiber membranes confined within a shell to form the module. The module, e.g., the container with the membrane element, is arranged to provide for the introduction of a feed stream, the means of collecting permeate that passes through the membranes, and the means for collecting nonpermeate/ retentate. The modules are so arranged as to prevent intermixing between the streams In some instances a plurality of modules are then connected via manifold means to feed inlet means and permeate exit means and retentate exit means Modifications further exist in which multiple bundles are contained in a single shell as discussed below.
In U.S. Pat. No. 3,722,694, issued Mar. 27, 1973 to E. A. Agranat, there is disclosed a filtration device in which the filter cartridges are arranged parallel to one another in an enclosure. The device is particularly applicable to ultrafiltration separations.
U.S. Pat. No. 4,187,180, issued Feb. 5, 1980 to Yasushi Joh, discloses another hollow fiber permeability apparatus wherein the hollow fiber cartridges are arranged in parallel relationship to one another in an enclosure and in which the enclosure includes inwardly formed constrictions around the longitudinal direction of the hollow fiber bundles arranged in parallel configuration.
U.S. Pat. No. 4,289,623, issued Sept. 15, 1981 to K. H. Lee, discloses a dialyzer construction having elongated tubular casing and a plurality of chambers so arranged in parallel relationship to each other that dialyzate flows from one casing end to the other through one of the passages around the hollow fibers and so to and from lengthwise through the other passages and finally out of the casing.
In the three references described above, the hollow fiber bundles are arranged in a configuration in which the sides of the bundles are in parallel alignment with one another and the enclosure or casing. The bundles are not in end-to-end alignment within an elongated cylindrical casing or shell.
U.S. Pat. N. 4,632,756, issued Dec. 30, 1986 to M. J. Coplan, et al., discloses a module composed of a single cylindrical shell having several fiber bundles extending in parallel relation to the shell. The arrangement disclosed in Coplan, et al., which configuration provides for relatively low packing density of the membrane area in a given shell volume, differs significantly from that of the invention described in this specification as will be seen hereinafter. In this reference the bundles are not all arranged in end-to-end serial alignment within a single elongated casing or shell.
U.S. Pat. No. 4,293,419, issued Oct. 6, 1981 to M. Sekino, et al., describes an apparatus based on a cylindrical pressure container divided into two longitudinal compartments by a dividing member at the substantial longitudinal center portion. In each compartment there is a hollow fiber assembly. In operation, the fluid to be treated is initially contacted with the exterior of one of the hollow fiber assemblies, the permeate is recovered and the retentate is passed into the second compartment and comes into contact with the exterior of the second hollow fiber assembly Permeate is recovered from the second assembly and final retentate is discharged. The apparatus disclosed by Sekino, et al. differs considerably from that of the instant specification since it provides for sequential contact of retentate from a first assembly to a second assembly. This is also true when a plurality of dual assemblies is employed in the construction shown in FIG. 6 of U.S. Pat. No. 4,293,419.
U.S. Pat. No. 4,451,369, issued May 29, 1984 to M. Sekino, et al., discloses a cylindrical multiple bundle permeator with bundles usually arranged in pairs having a common annular space filled with a collecting means connected to the adjacent tube sheets. Permeate flows through a dual passage connector to a common permeate outlet pipe. Feed flow is in series through the bundles and has a common annular flow passage only for each pair of bundles. The common central outlet pipe is segmented and there is no attachment means to each bundle. This multiple bundle arrangement is limited to radial flow configuration. The retentate from the first bundle becomes the feed for the next bundle in the series. The arrangement has a number of disadvantages. Each bundle is exposed to feed of a different composition and operates at different stage cut/recovery, and thus will produce permeate of different composition.
U.S. Pat. No. 4,652,373, issued Mar. 24, 1987 to J. L. Trimmer, discloses a wound hollow fiber permeator for producing processed water based on an improved tube sheet which is drilled with a hole pattern that cuts through all the hollow fibers to minimize losses caused by the presence of uncut fibers. The module's shell contains two bundles that operate in essentially radial flow configuration with permeate and retentate collected from a concentric tube arrangement.
U.S. Pat. No. 4,670,145, issued June 2, 1987 to D. W. Edwards, discloses a hollow fiber permeator containing a plurality of bundles and a tubular assembly that comprises a central outer tube the interior of which communicates with a first port at one end of the permeator casing and the exterior of said central outer tube, and an inner tube attached to and located within said central outer tube, said inner tube in communication with a second port at the end of the permeator casing opposite the first part. The bundles have an end mounted in an annular tubesheet and communicate with an annular chamber, this assembly removably mounted on said central outer tube. Means are also required for communication between each of said annular chambers with said inner tube. In addition the permeator contains a third port in the casing which is in communication with the exterior of said bundle assemblies. The bundles operate essentially in radial flow configuration.
Japanese Patent Application Sho 63-291605 published Nov. 29, 1988 discloses an apparatus for treating contaminated water. The invention provides means for providing an air back-flash or air scrubbing to remove suspended matter accumulated on the outside surface of the large diameter hollow fibers. The hollow fibers are arranged in a parallel configuration with filtrate collector tubes distributed throughout the hollow fiber bundle.